Alkylation process



Patented Oct. 24, 1944 v 2,361,356 ALKYLATION PROCESS Alexander N.Sachanen and Arlie A. OKelly, woodbury, N. J., and Robert H. Work,Philadelphia, Pa., asslg'nors to Socony-Vacuum Oil Company,Incorporated, New York, N. Y., a corporation of New York No Drawing.Application May 20, 1941, Serial No. 394,296

9 Claims. (Cl. mill-683.4)

This invention relates to the alkylation of paraflin hydrocarbons witholefin hydrocarbons and is concerned particularly with the production ofhigh octane motor fuel by the catalytic alkyla tion of normally gaseousparaflins with normally gaseous olefins.

It is known that olefinic gases may be polymerized thermally to producegasoline of an unsaturated character by treating at high temperaturesand pressures, as disclosed, for instance, by Wagner Patent No.2,088,824. Further, many processes are known for passing C3 and C4hydrocarbon gases along with cracking stock or naphthe through acracking furnace to crack and polymerize such gases to gasolinesimultaneousl with the cracking or reforming. Sullivan patents, Nos.2,022,221 and 2,145,900, Youker Patent No. 2,027,460, and OstergaardPatent No. 2,135,014, are a few of the many patents disclosing thislatter process. Also Towne Patent No. 2,090,272 separately cracksparaifinic gases to olefinic gases before passing the gases throughapolymerizing and reforming furnace with naphtha. Again, Tropsch PatentNo. 2,063,133 discloses a catalytic process for cracking andpolymerizing normally gaseous hydrocarbons, using elevated temperaturesand pressures and an organic halide catalyst.

It is also known that a paraflinic hydrocarbon may be combined directlywith an oleiinic hydrocarbon by thermal or catalytic alkylation toproduce a saturated alkylate product. Since conditions of alkylationalso usually will polymerize olefins, it is necessary to maintain arelatively low concentration of olefins in the reaction mixture duringalkylation. Several methods are known for the catalytic alkylation ofiso-parafiins with olefins. For instance,-it is known to alkylateiso-parafiins with olefins at low temperatures using sulfuric acid oraluminum chloride as a catalyst. However, such processes alkylate onlyisoparafiins. Further, the consumption of catalyst is comparativelyhigh, amounting to by weight or more with respect to the alkyiateproduct. In the non-catalytic, thermal alkylation of paraflins witholefins, high temperatures above 900 Rand very high pressures above3,000 lbs. per square inch are employed, which involve high initial andoperation costs.

It is an object of our invention to provide an eiilcient process forcatalytically alkylating parafiin hydrocarbons with olefin hydrocarbons.Another object of our invention is to provide an eiiicient process forcatalytically alkylating either normal parafiins or iso-paraiiins witholefins. A

more specific object is to provide a process for catalyticallyalkylating normally gaseous parafiins with normally gaseous olefins toproduce high yields of high octane gasoline.

Our invention comprises alkylating paraifinic hydrocarbons, which may beeither normal par aflins or isoparaifins or a mixture of the two, witholeflnic hydrocarbons at elevated temperatures and pressures in thepresence of a catalyst consisting essentially of an organic halide andany non-volatile metal which is capable of reacting with hydrogen halideunder the conditions of the process, and of these metals, aluminum andiron are preferred. In the co-pending Sachanen et al. application S. N.355,818, filed September 7, 1940, it is disclosed that parafiins, eithernor= mal or iso-, may be alkylated with olefins in the presence of acatalyst consisting essentially oi an organic halide. We now have, foundthat similar alkylations also may be effected using catalysts whichstill consist essentially of an or= ganic halide but which includcertain metals in combination with the organic halides, the metals alonebeing inert. The purity and par. afiinicity of the alkylate producedwith the combination of organic halides and metals is somewhat higherthan even that obtained in the case of the alkylation with organichalides alone. For instance, whereas the iodine number of the al-:kylates produced by the present process is around 0 to 8, that of thealkylates formed in the presence of organic halides alone is usuallyaround 10 or somewhat higher.

An important feature of the present invention is the" fact that,contrary to the conventional catalytic processes which are only capableof alkylating iso-parafiins, our process is capable of alkylating eithernormal paramns or iso-parafflns, and We obtain high yields of a highgrade product therefrom. Moreover, it should be pointed out that ourprocess is capable of efiecting essentially only alkylation so that analmost pure parafiinic product may be obtained.

An important feature of our process as com pared to a strictly thermalprocess is the relas tively low temperature used, not exceeding usually650-750 F. in a continuous operation, and

500 to about 3,000 pounds per sq. in. or more, the most suitablepressure being more or less dependent upon the particular temperatureemployed. In general, the higher the pressure, the higher the yield ofalkylate. Accordingly, the upper limit on pressure is set primarily bythe feasibility of maintaining such pressure.

An operation feature of our process that is of considerable practicalimportance is the fact that a very small amount of catalyst is required.In our operations, we prefer to use only about 1% or less of the organichalide catalyst with respect to the total charge of paraflins andolefins. Further, the consumption of the metal in the process is verysmall. Usually the weight of the metal after the alkylation in a batchprocess is approximately equal to its original weight.

The organic halide catalyst of this invention comprises organic halogenderivatives, wherein a halogen has been substituted for part or all ofthe hydrogen of an organic compound, the efficiency of the catalystapparently being somewhat in proportion to the ease with which it givesup hydrogen halide during the alkylation. In general, the preferredcatalysts are halogen derivatives of hydrocarbons, and, particularly,cheap chlorine derivatives, wherein the halogen is substituted onto anon-ring portion, if any, of the hydrocarbon. It is to be understoodherein that by derivatives of hydrocarbons, we mean compounds whereinall the hydrogen has been substituted, e. g., carbon tetrachloride, aswell as compounds wherein only part of the 4 hydrogen has beensubstituted, e. g., chloroform.

We especially prefer to use as our catalysts chlorinated derivatives oflight paraflinic hydrocarbons, including hydrocarbons of gasolineboilingrange. Thus, at the present time, we consider a chlorinated naphtha or achlorinated butane as the most feasible catalyst from a practicalstandpoint. However, other specific catalysts that may be mentioned byway of example of the compounds that may be used are: chloroform; carbontetrachloride; .dichloro-difluoro methane; dichloro-monofluoro methane;ethyl chloride; ethyl bromide; ethylene dichloride: trichlor-aceticacid; chloral: acetyl chloride;

' benzoyl chloride; benzyl chloride; and so forth.

It is to b understood also that free halogens or hydrogen halides,reacting with hydrocarbons, can be used to form our catalyst in situ.

To illustrate the invention further, we set forth below specificexamples of operation without, however, intending to be limited to thespecific details thereof.

Example I 600 parts by weight of iso-butane are reacted with 79 parts byweight of ethylene in the presence of 30 parts by weight of metallicaluminum (turnings) and 7 parts by weight of chloroform in an autoclaveat 625 and 3,000 lbs. per square inch pressure for thirty minutes; theproducts of the reaction were as follows:

Unreacted gases Alkylate boiling and loss up to Heavy ends Has aspecific gravity of 0.671 at 20 C. and an {iodine number of Exampie IIUnreacted gases Alkylate boiling and loss up to 0. Heavy ends 569 partsby weight or 94 parts by weight 12 parts by weight 84.3%. or 13.9%. or1.8%.

- The alkylate boiling up to 160 0. had a specific gravity of 0.680 at20 C. and an iodine number of 8.

We claim:

1. A process of alkylating paraffins with olefins which comprisescontacting the olefins and parafflns at a temperature between about 500F. and about 800 F. in the presence of a catalyst consisting essentiallyof an organic halide and a metal which is non-volatile and capable ofreacting with hydrogen halide under the conditions of the process andcontrolling the concentration of olefins so that alkylation is theprincipal reaction. v

2. A process of alkylating low boiling paraflins with low boilingolefins to produce saturated hydrocarbons of gasoline boiling rangewhich comprises contacting said paraflins and olefins at a temperaturebetween about 500 F. and about 800 F. and at a pressure above about 500pounds per square inch in the presence of a catalyst consistingessentially of an organic halide and a metal which is non-volatile andcapable of reacting with hydrogen halide under the conditions of theprocess and controlling the concentration of olefins so that alkylationis the principal reaction.

3. The process of claim 2 wherein the paraflin is selected from theclass consisting of propane and butanes and the olefin is selected fromthe class consisting of ethylene, propylene and butenes.

4. The process of claim 2 wherein the organic halide is a halogenderivative of a hydrocarbon wherein a halogen is substituted onto anon-ring carbon atom.

5. The process of manufacturing high octane gasoline which comprisesalkylating normally gaseous paraflins with normally gaseous olefins at atemperature between about 500 and about 800 F. and at a pressure aboveabout 500 pounds per square inch in the presence of a catalystconsisting essentially of a small amount of a chlorinated derivative ofa light paraffinic hydrocarbon and a metal which is non-volatile andcapable of reacting with hydrogen halide under the conditions of theprocess, and controlling the concentration of olefins so that alkylationis the principal reaction.

6. The process of claim 5 wherein the parailin is a butane and theolefin is ethylene.

'7. The process of manufacturing high octane gasoline which comprisesalkylating a butane with a normally gaseous olefin at a temperaturebetween about 500 and about 750 F. and at a pressure above about 500pounds per square inch in the presence of a catalyst consistingessentially of a small amount of a chlorinated derivative of a lightparaffinic hydrocarbon, not ex- 9. A process of alkylating paraiiinswith oleiins which comprises contacting the paraflins and oleiins underconditions or aikylation at a temperature between about 500 F. and about800 F, in the presence of a catalyst consisting essentially 01 anorganic halide and aluminum:

ALEXANDER N. SACHANEN. ARLIE A. OKELLY. ROBERT H. WORK.

